Apparatus for investigating earth formations



Sept. 8, 1959 R. Q. FIELDS 2,903,071

APPARATUS FOR INVESTIGATING EARTH FORMATIONS Filed Sept. 2a, 1955 :s Sheets-Sheet 1 |G l L 4 L as 7 32a 400 i 9/ 40b INVENTOR ROGER Q FIELDS W/W A w.. 1//// WMAIIFLIMJKI: Al i A HIS ATTORNEY.

R. Q. FIELDS 2,903,071

APPARATUS. FOR INVESTIGATING EARTH FORMATIONS Sept. 8, 1959 3 Sheets-Sheet 2 Filed Sept. 23, 1955 I pIrI INVENTOR. ROGER Q-FIELDS. BY W #rqqfihflfi HIS ATTORNEY.

P 3, 5 R. Q. FIELDS I 2,903,071

APPARATUS FOR INVESTIGATING EARTH FORMATIONS Filed Sept. 23, 1955 3 Sheets-Sheet 3 INVEN TOR.

ROGER Q, FIELDS. BY 6301x640 p eg HIS ATTORNEY.

United tent APPARATUS FOR [NVESTIGATING EARTH FORMATIONS Roger Q. Fields, Houston, Tex., assignor, by mesne assignments, to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Application September 23, 1955, Serial No. 536,204

17 Claims. (Cl. 166-100) This invention relates to apparatus for investigating earth formations and, more particularly, pertains to a new and improved earth formation fluid sampler adapted to be lowered through a borehole to a position adjacent an earth formation to be investigated for fluid content.

One type of fluid sampler proposed heretofore comprises a hollow projectile disposed within a gun block adapted to be lowered through a borehole to a position adjacent a formation of interest. At the desired level, an explosive contained by the gun block is detonated thereby to fire the projectile into the formation. The projectile is connected to a reservoir by a flexible tube and has a normally closed front aperture which is opened so that formation fluid may pass through the projectile and the flexible tube into the reservoir where it is retained by means of a check valve. The apparatus may then be raised to the surface where the sample can be recovered from the reservoir.

While the just-described arrangement may operate satisfactorily in some cases it may not always provide reliable results. In particular, after a sample is drawn into the reservoir and the fluid connection with the formation is broken by withdrawing the projectile, the check valve is exposed to the drilling liquid usually contained by the borehole. Since the pressure of the drilling liquid is customarily greater than the pressure of fluid in the formations and thus is greater than the pressure of fluid in the reservoir, the check valve may open to the drilling mud and the sample may be undesirably contaminated.

It is an object of the present invention, therefore, to provide a new and improved earth formation fluid sampler capable of extracting a sample of formation fluid with a greater degree of reliability than heretofore possible.

Another object of the present invention is to provide a new and improved earth formation fluid sampler which may be employed to obtain a sample of formation fluid free of contamination by drilling mud.

An earth formation fluid sampler in accordance with the present invention comprises a support adapted to be positioned adjacent a selected formation and having means in said support defining a sample-conveying conduit and a gun bore, a formation-penetrating projectile in the gun bore, a propellant for impelling the projectile toward the selected formation, and a tube. One end of the tube is connected to the projectile for entry of a fluid sample and the tube is effectively extendable between the projectile and from the gun bore. The fluid sampler further comprises a valve mechanism fluidly connecting the remaining end of the tube and the sample conveying conduit. The valve mechanism has one operating condition providing a fluid communication path between the tube and the sample-conveying conduit and is transferable to a second condition in which this path is effectively closed in response to relative displacement between the support and the tube.

The novel features of the present invention are set forth with particularity in the appended claims. The

present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying rawings in which:

Fig. 1 is a perspective view of an earth formation fluid sampler embodying the present invention and shown in one condition of operation in a borehole traversing a number of earth formations;

Fig. 2 is a cross sectional view of the apparatus shown in Fig. 1 taken along lines 22 and drawn to an enlarged scale;

Fig. 3 is a cross sectional view of a portion of the apparatus shown in Fig. 2 taken in the plane of Fig. 2, but drawn to an enlarged scale and rotated in the viewing plane through an angle of Fig. 3A is a plan view of one of the elements shown in Fig. 3 drawn to an enlarged scale;

Fig. 4 is a fragmentary cross sectional view drawn along line 44 of Fig. 3.

Fig. 5 is a view similar to the one of Fig. 2, but illustrating another condition of operation for the appara-ms.

In Fig. 1 of the drawings, the earth formation fluid sampler embodying the present invention is shown disposed in a borehole 10 traversing earth formations 11, 12, 13 and containing a drilling fluid 14, such as a water base or oil base mud. It is assumed that formation 12 is the one of interest from which a fluid sample is to be obtained in a manner to be more apparent from the discussion to follow.

The fluid sampler comprises a support including a cable head 15 from the lower end of which a pair of side rails 16 and 17 extend. The lower extremities of side rails 16 and 17 are terminated by an end block 18 and a conventional centralizer 19 extends from end block 18. The centralizer may, for example, include a plurality of bowed springs arranged in the usual manner to center the apparatus in borehole 10. A supporting cable 20 extends upwardly from cable head 15 and may be employed in connection with a winch (not shown) located at the surface of the earth to lower and raise the apparatus in the borehole in the customary manner.

Mounted between side rails 16 and 17 is a first sampler unit comprised of a gun block 21 positioned below a sample-receiving chamber 22. A second, similar sampler unit comprised of a gun block 23 and a sample-receiving chamber 24 is mounted between the side rails below the first sampler unit. Of course, although but two sampler units have been illustrated, obviously, side rails 16 and 17 may be suitably extended to accommodate any desired number of additional units.

As will be more apparent from the discussion to follow, the gun blocks 21 and 23 have individual gun bores each adapted to receive a formation-penetrating projectile, a propellant for impelling the projectile toward the selected formation and an extensible tube having ends connected between the projectile and the gun bore for receipt of the sample fluid. In order to actuate or detonate the propellant in each of the gun bores, electrical conductors 25, 26 and 27 connected to suitable detonators, one of the detonators 25' being shown in Figs. 2 and 3. The con ductors associated with the detonators extend to the surface of the earth through cable 20. A selector switch 28 is provided for selectively connecting each of the firing circuits to a source of electrical energy, such as a battery 29 which may have in circuit therewith a rheostat 30 and a current indicating meter 31.

Referring now to Fig. 2, illustrating in longitudinal cross section the details for the sampler unit comprised of gun block 21 and sample-receiving chamber 22, it will be seen that gun block 21 is provided with a transverse cylindrical bore 32 which receives a projectile assembly 33. The projectile assembly 33 is comprised of a projectile including a fore portion 34 extending forwardly from a base or rear portion 35 whose maximum diameter conforms to the diameter of bore 32. An annular recess 36 in base 35 receives an O-type sealing ring 37 providing a fluid seal between the base of the projectile and the gun bore. Thus, base portion 35 is adapted for a gas-tight, slidable fit in gun bore 32 and has a length relative to the axis of the gun bore suificient to minimize tilting of the projectile as it travels through the gun bore.

Fore portion 34 has an area in a vertical cross sectional plane that is considerably smaller than the cross sectional area of rear portion 35, the two portions being connected by a transition section 38. By providing a forward portion 34 of reduced diameter, increased penetration may be attained, as disclosed in the copending application of Maurice Mennecier, filed September 23, 1955, bearing the Serial No. 536,251 and assigned to the same assignee as the present invention. Of course, the length of forward portion 34 is limited by the length of gun bore 32.

A hollow, cylindrical container 39 extends from the rear end of base 35 and is terminated by a member 40 which effectively closes the rear end of gun bore 32 and thus defines a false bottom for the gun bore. Projectile assembly 33 will be described in detail hereinafter in connection with Fig. 3. Briefly stated, member 40 contains a valve mechanism fluidly connected to a sample-conveying conduit '41 which extends upwardly from the periphery of gun bore 32.

Assembly 33 may be fabricated as a unit adapted to be inserted into the forward end of gun bore 32. The assembly may then be pushed backwardly until a small threaded extension 42 of member 43 passes through a corresponding opening 43 in a portion of the gun block 21 defining a rear wall 32a for bore 32 of gradually decreasing diameter. The wall 32a has a configuration conforming very closely to the corresponding surface of member 44 thereby to assist in maintaining a fluid seal. The periphery of opening 43 has an annular groove 40a for receiving an O ring 40b and the opening is enlarged at its rearmost end to provide a seat for a washer 40c and a fastener, such as a threaded nut 44. The extension42 is thus sealed in opening 43 and the projectile assembly 33 is secured in its position within the gun bore.

The upper end of fluid-conveying conduit 41 is terminated at the lower, conical surface 45 of a cylindrical opening 45a formed in the upper end of the gun block. The opening 45a receives and is fluidly sealed to a cylindrical projection 46 extending downwardly from sample chamber 22, the sample chamber being positioned with its lower surface 47 in engagement with the upper surface 48 of the gun block. An opening 49 extends upwardly through projection 46 to a check valve 56 fluidly connected to a tube 51 extending upwardly through the hollow interior 52 of sample-receiving chamber 22.

As will be more apparent from the discussion to follow, in operation a fluid sample may flow via sample-conveying conduit 41, opening 45, opening 49, check valve and tube 51 into the cylinder 52. The tube 51 provides a trap space for receiving extraneous fluid that may flow after a sample is drawn into the cylinder 52.

The upper end of the sample-receiving chamber 22 is provided with a closure 53 having a transverse opening 54 in fluid communication with a vertical port 55. A poppet valve 56 is threadediy received in one end of opening 54 and is arranged normally to close port 55. A hex socket (not shown) in poppet valve 56 permits manipulation of the valve. Thus, by removing a threaded plug 57 normally positioned in the remaining end of opening 54, the poppet valve 56 may be manipulated to its open position and a sample may flow from the sample chamber via port and opening 54.

As may be evident in Fig. 1, gun block 21 is secured to the side rails 16 and 17 by a plurality of screws or bolts, such as the bolts 58, which pass through the side rail 17. The gun blocks thus are permanently secured between the side rails. The sample-receiving chambers, on the other hand, are easily removed. To this end, the upper extremity of closure 53 is provided with an indentation 59 which receives the lower, pointed end 60 of a threaded rod 61. The other end of the threaded rod is received by a threaded opening (not shown) which in this case is in the bottom of cable head 15. For example, as shown at the lower extremity of Fig. 2, a threaded rod 62 extends into a threaded opening 63 at the lower end of gun block 21. Rod 62 similarly has a lower pointed end which serves as a securing means for the samplereceiving chamber 24. A channel 64 extends transversely from the upper end of opening 63 to the rear surface of the gun block so that any drilling fluid which may leak into the space between the upper end of rod 62 and the confronting wall of opening 63 is pressure equalized. Therefore, pressure build-up in this space is minimized and the threaded rod may be easily removed. If desired, a locking nut 65 may be provided to secure threaded rod 62.

In order to insert a sample chamber into operative relation with a corresponding gun block, such as the chamber 22, the threaded rod 61 shown at the upper part of Fig. 2 is rotated by means of a suitable tool applied to a non-circular rim 66. The direction of rotation is selected to displace the rod upwardly. This provides space in which to introduce the sample chamber 22 and the lower projection 46 is inserted in opening 45a. Thereafter, the rod 61 is rotated in the opposite direction to carry it downwardly until end 60 is firmly engaged wth the depression 59 and the associated locking nut (similar to the one designated 65 at the lower extremity of Fig. 2) is tightened. After a sample has been obtained, the sample-receiving chamber is removed simply by loosening the locking nut, rotating screw 61 and raising the sample chamber slightly.

As may be seen in Fig. 3, the rear end of base portion 35 of the projectile is provided with an annular recess and the front end of false bottom 40 has a similar recess 71. The corresponding ends of container 39 are rolled into the recesses 70 and 71 to form the unitary assembly 33 described in connection with Fig. 2.

Fore portion 34 of the projectile has a forwardly extending tapered section 34a of generally frusto-conical configuration. An axial opening 341; in section 34a receives and is fluidly closed and sealed by a bullet-shaped plug 34c having an integral shear ring 34d abutting the junction between the outer surface of section 34a and the wall of opening 34b. Thus, opening 341) constitutes a first, normally closed passage and it is in fluid communication with a chamber 35a extending coaxially through portions 34 and 35 of the projectile. As will be seen from the following discussion, when the projectile is impelled into a formation of interest, the force of impact shears ring 34d and the plug 340 is forced into chamber 35a by the flow of formation material. Accordingly, compaction of the formation material is minimized as pointed out in the copending application of Maurice P. Lebourg and Roger Q. Fields, filed September 23, 1955, bearing the Serial No. 536,189 and assigned to the same assignee of the present invention, where the projectile arrangement just described is disclosed and claimed.

In certain applications, a projectile of the type illustrated in Fig. 9 of Patent 2,055,506 may be employed. Preferably, other varieties of non-compaction projectiles may be utilized, such as those described and claimed in either of the following applications assigned to the present assignee:

Application Serial No. 536,190, of Andre Blanchard, filed September 23, 1955.

Application Serial No. 536,115 of MauriceP. Lebourg, filed September 23, 1955.

y A fluid filter unit 35b is positioned at the rear end of chamber 35a adjacent an insert 35c threaded into a coaxial opening 35d in the rear end of base portion 35 where it is fluidly sealed. Insert 350 has a central opening 73 having outwardly flared, conical sections 74 and 75. The filter unit 35b has a generally cylindrical body having lateral openings extending between the outer cylindrical surface and a central bore. A wire screen of suitable mesh size to filter out solid material is secured around the outer cylindrical surface of the filter body. The mesh size, of course, is selected to provide an optimum filtering action in accordance with the type of formation expected to be encountered.

One end of a flexible tube 76 extends through opening 73 and is thus in fluid communication with filter 35b. It is provided with an outer rim 77 disposed in section 74. Rim 77 is greater in diameter than opening 73 so that the tube is effectively mechanically connected to projectile 34, 35. Moreover, the tube preferably is silver soldered to the Wall of opening 73 and thus is fluidly sealed thereto. Flared section 75 serves to minimize sharp bending of tube 76 during the portions of an operating cycle prior to rupturing of the tube.

Tube 76 is wound into a close helix having a diameter essentially equal to the inner diameter of container 39 and is constructed of a relatively flexible material so that it is extensible as the projectile 34, 35 is driven out of the gun bore 32 under the influence of an explosive propellant 78. For example, black smokeless powder may be employed and fills the space within the cylinder defined by the helix of tubing 76. Obviously, the tubing must be strong enough, i.e., have a wall thickness great enough, to resist the explosive force of the propellant. On the other hand, it must be flexible enough so that it does not impede movement of the projectile. In addition, the tubing should have a preselected breaking strength. To achieve these specifications in a particular practical embodiment of the invention, stainless steel tubing of dead soft quality and identified by No. 304 having an outer diameter of A2" and having an inner diameter of was successfully employed.

The forward end of false bottom 40 has a cylindrical section 79 of reduced diameter and the space thus provided is filled with the explosive 78. Accordingly, a puncturing instrument may be inserted through a lateral opening (not shown), in the side of gun block 21 to make an opening in container 39. Thereafter, a conventional electrical igniter 25 may be positioned with its heater element extending into the aforesaid space so that the forward portion of the detonator extends into the explosive propellant 78. Detonator 25 may be, for example, of the type shown in U.S. Patent No. 2,681,701 to M. Schlumberger. Appropriate electrical connections (not shown) extend from the igniter to corresponding ones on the cable conductors 2527 so that the heater of the igniter may be energized to detonate the explosive.

The remaining end of tubing 76 is received by and mechanically connected to the periphery of an opening 80 extending coaxially through a cylindrical control ele ment 81 of a valve mechanism. Control 81 is slidably disposed within a bore including sections 82a and 82b of slightly different diameter extending at an angle through member 40. Preferably, this angle is arranged so that the axis of bore 82a, 82b is essentially perpendicular to a generally conical transition section 40 that connects the body of member 40 and extension '42. Of sections 82a and 82b, section 82a, which receives the tube-receiving end 81a of member 81, is the larger and has a diameter providing a close, sliding fit. Section 82b similarly provides a close, sliding fit for portion 81b of control element 81.

In the operative position of the control element 81 illustrated in Fig. 3, a transverse extension 83 of opening 80 is aligned with a conduit 84 that extends from the periphery of bore 82b in a direction transverse to the longitudinal axis of bullet assembly 33. Conduit 84 terminates at the exterior surface of the false bottom 40. Fluid communication between conduit 84 and sample-conveying conduit 41 is completed by a recess 85 circumferentially disposed about member 40, the lower end of conduit '41 being positioned so that it fluidly connects with recess 85 when member 40 is in bore 32 with section 40' seated on wall 32a, as best seen in Fig. 2. Another similar recess 86 is disposed in front of the recess 85 and these annular recesses function as a labyrinth which separates a pair of O-type sealing rings 87 and 88 which protect the rear end of the gun bore from the force of the explosion of propellant 78.

Threaded into an opening extending axially from the rear end of control member 81 is a bolt 90 securing a pair of similar washers 91 and 92 between its head and the rear end of the control member. The head of bolt 90 and washers 91 and 92 are movable with the control member through an enlarged section 93 of bore 82a, 82b, and a transition section 94 between the sections 82b and 93 serves as a stop for the control member when engaged by the washers. In this connection washer 92 serves as a cushion to prevent damage to washer 91.

The washer 91 is constructed of a thin, resilient or spring-like material having a plurality of peripheral fingers 91 a, as seen in Fig. 3A engaging the wall of bore section 93. The fingers are deformed toward the rear end of this bore section and are arranged so that they tend to straighten themselves to provide an extended diameter for washer 91 that is greater than the diameter of bore section 93. Thus, although control member 81 may slide in a forward direction, once displaced it cannot move backward because any rearward movement is accompanied by a frictional or cutting engagement between the edges of washer 91 and the wall of bore 93.

In order releasably to lock the control member 81 in the position shown, a shear pin 95 passes through the head of bolt 90 and into appropriate openings extending transversely from the wall of bore 93. The shear pin is constructed in a known manner so that it shears with the application of a force on the order of 55 pounds. When tube 76 is extended and engages the outer rim of bore 32, a pulling force in a range from 200 to 800 pounds may be required to shear the pin 95 and displace control member 81 with respect to member 40.

Although the control member 81 is slidable in its bore 82a, 82b a gas-type seal is provided by a series of O-type rings 96, 97 and 98. However, a gas pressure communication path exists between the front surface 99 of the control member 81 and a rear surface 100 defined by a surface of washer 91. This path is provided by a channel 101 (Fig. 4) extending between the front and rear surfaces of the member 40. Preferably channel 101 is filled with a presstlretrarrsmitting fluid, such as a silicone grease, so that the pressure produced by the detonation of the propellant is transmitted to surfaces 99 and 100. Thus pressure is imposed simultaneously on both ends of control element 81. It should be noted that with respect to any forces (developed on control element 81 resulting from gas pressure applied to its ends, the effective areas of the control element are defined by control element portion 81:: and bore section 8211, and portion 81b and bore section 82b, respectively. These areas are selected so that the one defined as 81a, 82a is slightly larger than the one s designated 82b, 8112 so that a very small net force is developed to urge the control member 81 in a backward direction. However, since the head of bolt 90 is normally in engagement with the wall section 32a (Fig. 2) of bore 32, movement of the control member cannot occur when propellant 78 is detonated.

To condition the fluid sampler for operation, sample chambers 22 and 24 may be evacuated or filled with a fluid at a pressure lower than the pressure of formationfluids. For example, the chambers may contain air at atmospheric pressure before they are installed and the apparatus is lowered into borehole 10 as shown in Fig. 1. When gun block 21 is opposite formation 12 from which a sample is tobe taken, an electrical circuit with battery 29 is completed by means of switch 28 and the igniter associated with gun block 21 is energized. Thus, propellant 78 is detonated and the force of the resulting explosion drives the projectile portions 34, 35 and 38 out of gun bore 32. Since the effective areas of control 81 are of essentially the same size, the force of the ex plosion does not displace the control member from the position shown in Fig. 3 and any slight tendency toward rearward movement is arrested by engagement between the end of bolt 90 and the wall section 32a.

Tubing 76 is arranged to uncoil at a force less than required to break pin 95. Moreover, because of the speed of projectile 34, 35 the coils of tubing open quickly, one coil at a time, and inertia, as well as the shear pin, operate to prevent movement of control member 81. Thus, the valve remains open as the projectile is impelled toward the formation.

As shown in Fig. 5, as the projectile imbeds itself in the formation, plug 340 is displaced inwardly by formation material. Thus, its normally closed aperture 34a opens to admit a sample of formation fluid. This fluid then flows through chamber 35a, filter 35b, tubing 76,

channel sections 80 and 83 of control member 81 (Fig. 3), conduit 84, annular recess 85, sample-conveying conduit 41 (Fig. 2), check valve 50, tube 51 and into space 52 of chamber 22 where the sample is retained. After the elapse of a predetermined interval of time, such as ten minutes, permitting the chamber 22 to become substantially filled, cable 20 is drawn upwardly to raise supports 18, gun block 21 being thus carried to the position shown in Fig. 5. When the force exerted on control member 81 exceeds 55 pounds, pin 95 is sheared and the control member is drawn forwardly through bore 82a, 82b until the washer 92 engages transition section 94. Thus, channel section 83 is carried away from alignment with the conduit 84 and the valve mechanism is effectively closed. Because of the action of spring washer 91, the valve is releasably locked in the closed position completely blocking sample-conveying conduit 41 to fluid flow.

When the pull exerted on cable produces a force on the tubing 76 that exceeds 800 pounds, the tubing breaks and the entire apparatus may be drawn from the borehole. Of course, in some instances the projectile may be withdrawn before the tubing is broken thus permitting the apparatus to be raised. At the surface of the earth, sample-retaining chamber 24- may be removed in the manner described hereinbefore so that the fluid sample may be analyzed.

From the foregoing discussion it is evident that a fluid sampling device constructed in accordance with the present invention provides a reliable and highly effective means for obtaining a sample of fluid from an earth formation. Specifically, since the sample-conveying conduit 41 is closed by the positive action of control element 81 of the valve mechanism after a sample is obtained, the pressure of fluid within the sample-retaining chamber 22 is maintained at a pressure which is representative of the pressure of fluids in the formation of interest. Moreover, there is no possibility of the sample being contaminated by drilling mud after the tube 76 is broken. At the surface of the earth, a pressure gauge may be connected to the opening 54 before poppet valve 56 is opened and accurate pressure indications may be obtained.

Through the use of a pressure balanced valve mechanism in accordance with the present invention, more reliable operation than heretofore possible is achieved although the mechanism is exposed to the explosive force of'propellant 78. In addition, even though the valve mechanism is exposed to the drilling mud, since it is pressure balanced, the operation to the valve mechanism is not adversely affected by the pressure of the drilling mud.

If desired, a conventional pressure gauge 22a (Fig. 2), for example, as shown by the Patent No. 2,441,894 to M. Mennecier may be mounted to support 1518 and placed in fluid communication with the sample-retaining chamber 22. This gauge may be of the continuously recording or of the maximum pressure types, or may be arranged to provide an electrical signal representative of the pressure within the chamber. In the latter case, appropriate electrical conductors may be provided so that pressure indication may be derived at the surface of the earth.

As pointed out earlier, the tubing 76 which connects projectile 34, 35 with member 81 of the valve mechanism must be flexible and yet must be able to withstand the force of the explosion of propellant 78. Obviously, if a tube having a greater inner diameter is desired, its wall thickness must be correspondingly increased to obviate crushing of tubing, but its flexibility may be detri mentally reduced. This may be overcome by using a thin' Walled tubing and filling the tubing with a relatively incompressible fluid. Although the filling material will appear in mixture with the sample of formation fluid, an appropriate choice of material will make it easily separable and readily identifiable from the sample, as is characteristic of a silicone grease, for example.

The amount of pull on tubing 76 necessary to shift control element 81 may be reduced by decreasing the friction of the tubing on the mouth of bore 32. For example, a roller may be appropriately positioned at the mouth of the bore so that it is engaged by the tubing.

While a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects, and therefore the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a selected formation; means in said support defining a sample-conveying conduit and a gun bore; a formation-penetrating projectile received in said gun bore and having a hollow portion, said projectile further having a forward Wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow; means in said gun bore for impelling said projectile toward the selected formation; a flexible tube in said gun bore having one end connected to said projectile and being fluidly connected to the hollow portion of the projectile for entry of a fluid sample, said tube being effectively extendable between said projectile and said gun bore; a valve mechanism in said support fluidly connecting the remaining end of said tube and said sample-conveying conduit and including a movable control member mechanically connected to said remaining end of said tube and responsive to relative displacement between said support and said tube to alter the operative condition of said valve mechanism.

2. An earth formation fluid sampler comprising: a sup port adapted to be positioned adjacent a selected formation; means in said support defining a sample-conveying conduit and a gun bore; a formation-penetrating projectile received in said gun bore, said projectile having a hollow portion and having a forward wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow; a propellant in said gun bore for impelling said projectile toward the seiected formation; a. flexible tube having one end connected to said projectile and being fluidly connected to the hollow portion of the projectile for entry of a fluid sample, said tube being effectively extendable relative to said support; and a valve mechanism in said support fluid-- ly connecting the remaining end of said tube and said sample-conveying conduit and including a movable control member mechanically connected to said remaining end of said tube, said control member having opposed, effective surfaces of essentially equal areas exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant, and said control member being movable in response to relative displacement between said remaining end of said tube and said support to alter the operative condition of said valve mechanism.

3. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a selected formation; means in said support defining a sample-conveying conduit; means in said support defining a gun bore; a formation-penetrating projectile received in said gun bore, said projectile having a hollow portion and having a forward wall portion adapted to open said hollow portion when the projectile is in the formation to permit fluid flow; a propellant disposed within said gun bore for impelling said projectile toward the selected formation; a flexible tube having one end connected to said projectile for entry of a fluid sample and being fluidly connected to the hollow portion of the projectile, said tube being extendable between said projectile and said gun bore; and a valve mechanism in said support fluidly connecting the remaining end of said tube and said sample-conveying conduit and including a movable control member mechanically connected to said remaining end of said tube, said control member having opposed, eflective surfaces of essentially equal areas exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant and said control member being movable in response to said relative displacement between said remaining end of said tube and said support to alter the operative condition of said valve mechanism.

4. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a selected formation; means in said support defining a sample-conveying conduit; means in said support defining a gun bore; a formation-penetrating projectile received in said gun bore and having a hollow portion normally closed by a forward wall portion adapted to be opened to fluid flow after said projectile is imbedded in the selected formation; a propellant disposed within said gun bore for impelling said projectile toward the selected formation; a flexible tube having one end mechanically connected to said projectile and being fluidly connected to the hollow portion of the projectile for entry of a fluid sample and eflectively extendable between said projectile and said gun bore; and a valve mechanism in said support fluidly connecting the remaining end of said tube and said sample-conveying conduit and including a movable control member mechanically connected to said remaining end of said tube, said control member having opposed, eflective surfaces of essentially equal areas exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant, and said control member being movable in response to relative displacement between said remaining end of said tube and said support to alter the operative condition of said valve mechanism.

5. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a selected formation; means in said support defining a sample-conveying conduit; means in said support defining a gun bore; a formation-penetrating projectile received in said gun bore and having a hollow portion, said projectile further having a forward wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow; a propellant in said gun bore for impelling said projectile toward the selected formation; a flexible tube in said gun bore having one end connected to said projectile for entry of a fluid sample and effectively extendable between said projectile and said gun bore; anda valve mechanism in said support fluidly connecting the remaining end of said tube and said sample-conveying conduit and including a movable control member me-" chanically connected to said remaining end of said tube; said control member having opposed, effective surfaces of essentially equal areas exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant, and said control member having a first position fluidly communicating said conduit withsaid tube and being movable in response to relative displacement between said remaining end of said tube and said support to a second, essentially locked position. wherein fluid communication between said conduit and said tube is interrupted.

6. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a selected formation; means in said support defining a sample-conveying; conduit; means in said support defining a gun bore; a formation-penetrating projectile received in said gun bore and having a hollow portion, said projectile further having a forward wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow; a propellant in said gun bore for impelling said projectile toward the selected formation; a flexible tube in said gun bore having one end connected to said projectile for entry of a fluid sample and being fluidly connected to the hollow portion of the projectile and being effectively extendable between said projectile and saidgun bore; and a valve mechanism in said support fluidly connecting the remaining end of said tube and said sample conveying conduit and including a movable control member mechanically connected to said remaining end of said tube, said control member having opposed, effective surfaces of essentially equal areas exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant, said valve mechanism further including locking means for releasably holding said control member in a first position effectively opening said valve mechanism to fluid flow, said locking means maintaining said control member in said first position and being responsive to a force greater than a given amount produced by relative displacement between said remaining end of said tube and said support to permit. said control member to pass toward a second position eifectively closing said valve mechanism to fluid flow.

7. An earth formation fluid sampler comprising: a sup-u port adapted to be positioned adjacent a selected forma-- tion; means in said support defining a first sample-conveying conduit; means in said support defining a gun: bore, said last-mentioned means being in fluid communication with said sample-conveying conduit; a formationpenetrating projectile received in said gun bore and having a hollow portion, said projectile further having a forward wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow; a propellant in said gun bore for impelling said projectile toward the selected formation; a flexible tube in said gun bore having one end mechanically connected to said projectile and being fluidily connected to the hollow portion of the projectile for entry of a fluid sample, said tube being effectively extendable between said projectile and said gun bore; and a valve mechanism including a body conforming to and disposed within the rear end of said gun bore, said body having an annular recess disposed, at least in part, adjacent said conduit, said body further having a valve chamber and having a second conduit connecting said recess and said valve chamber, a movable control member positioned within and closing said valve chamber and having opposed, effective surfaces of essentially equal areas exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant, said control member being connected to the remaining end of said tube and having a. third conduit establishing fluid communication between 11 said tube and said second conduit in a first position of said control member, and said control member being movable in response to relative displacement between said remaining end of said tube and said support to a second position interrupting fluid communication between said second and said third conduits.

8. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a selected formation; means in said support defining a first sample-conveying conduit and a gun bore; a formation-penetrating projectile received in said gun bore and having a hollow portion, said projectile further having a forward wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow; a propellant in said gun bore for impelling said projectile toward the selected formation; a flexible tube in said gun bore having one end mechanically connected to said projectile and being fluidly connected to the hollow portion of the projectile for entry of a fluid sample, said tube being efiectively extendable between said projectile and said gun bore; and a valve mechanism including a body conforming to and disposed within the rear end of said gun bore, said body having an annular recess disposed, at least in part, adjacent said conduit, having a valve chamber and having a second conduit connecting said recess and said valve chamber, a movable control member positioned within and closing said valve chamber and having opposed, effective surfaces of essentially equal areas, one of said surfaces being adjacent said propellant and thereby exposed to gas from said propellant, and said body having a channel effectively exposing the other of said surfaces to gas from said propellant, an essentially noncompressible liquid filling said channel to produce a force on said other surface substantially equal to the force on said one surface upon detonation of said propellant thereby to minimize movement of said control member, said control member being mechanically connected to said remaining end of said tube and movable in response to relative displacement between said remaining end of said tube and said support to a second position interrupting fluid communication between said second and said third conduits.

9. Apparatus for deriving a plurality of samples of earth formations traversed by a borehole comprising: a support adapted to be lowered in a borehole and selectively positioned adjacent a formation; a plurality of sampler units carried by said support in spaced relationship relative to a longitudinal axis for said support, each of said sampler units including a gun block, said gun block having a sample-conveying conduit and a gun bore, a formation-penetrating projectile in said gun bore and having a hollow portion, said projectile further having a forward wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow, a propellant in said gun bore for impelling said projectile toward the selected formation, and a flexible tube having one end mechanically connected to said projectile and being fluidly connected to the hollow portion of the projectile for entry of a fluid sample, said tube being effectively extendable between said projectile and said gun bore, a valve mechanism in said support fluidly connecting the remaining end of said tube and said sample-conveying conduit and including a movable control member mechanically connected to said remaining end of said tube, said control member having opposed, eifective surfaces of essentially equal areas exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant, and said control member being movable in response to relative displacement between said remaining end of said tube and said gun block to alter the operative condition of said valve mechanism, and a removable sample-receiving chamber coupled to said sample-conveying conduit; and means for selectively actuating the propellant of each of said sampler units.

10. An earth formation fluid sampler comprising: a sup- 12 port adapted to be positioned adjacent a selected forma-- tion; means in said support defining a sample-conveying conduit; means in said support defining a gun bore; a formation-penetrating projectile received in said gun bore and having a hollow portion, said projectile further having a forward wall portion arranged to open said hollow portion when the projectile is in the formation to permit fluid flow; means in said gun bore for impelling said projectile toward the selected formation; a flexible tube disposed in said gun bore and having one end connected to said projectile for entry of a fluid sample and being fluidly conneqted to the hollow portion of the projectile, said tube being extendable between said projectile and said gun bore; and a valve mechanism in said support fluidly connecting the remaining end of said tube and said sample-conveying conduit and including a movable control member responsive to relative displacement be-- tween said support and said tube to alter the operative condition of said valve mechanism, said control member being mechanically connected to said remaining end of said tube.

11. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a formation of interest; means in said support defining a sample-conveying conduit; an effectively extendable, flexible tube carried by said support and having one end movable relative to said support; means in said support for displacing said one end of said tube toward and into the formation of interest; and a valve mechanism in said support for fluidly connecting the remaining end of said tube and said sample-conveying conduit including a valve body and a bore therein, a control member in said bore responsive to relative displacement between said support and said tube to alter the operative position of said valve mechanism, said control member being mechanically connected to said remaining end of said tube and movable relative to said valve body between open and closed operating positions, said valve body and control member having fluid conduits therein arranged to permit fluid communication in said open position and to prevent fluid communication in said closed position.

12. An earth formation fluid sampler adapted to be lowered by a cable into a borehole penetrating earth formations comprising: a support carried by the cable and adapted to be positioned adjacent a formation of interest, means in said support defining a sample-conveying conduit; an eifectively extendable flexible tube carried by said support and having one end movable relative to said support, said tube exhibiting a break strength so that it severs on the application of a tensile force lower than the tensile force at which the cable may be broken; means in said support for displacing said one end of said tube toward the formation of interest; and a valve mechanism in said support for fluidly connecting the remaining end of said tube and said sample-conveying conduit including a valve body and a bore therein, a control member in said bore responsive to relative displacement between said support and said tube to alter the operative position of said valve mechanism, said control member being mechanically connected to said remaining end of said tube and movable relative to said valve body between open and closed operating positions, said valve body and control member having fluid conduits therein arranged to permit fluid communi cation in said open position and to prevent fluid communication in said closed position.

13. An earth formation fluid sampler adapted to be lowered by a cable into a borehole penetrating earth formations comprising: a support carried by the cable and adapted to be positioned adjacent a formation of interest, means in said support defining a sample-conveying conduit; an effectively extendable flexible tube carried by said support and having one end movable relative to said support, said tube exhibiting a break strength so that it severs on the application of a tensile force lower than the tensile force at which the cable may be broken; means in said support for displacing said one end of said tube toward the formation of interest; a valve mechanism in said support for fluidly connecting the remaining end of said tube and said sample-conveying conduit including a valve body and a bore therein, a control member in said bore responsive to relative displacement between said support and said tube to alter the operative position of said valve mechanism, said control member being mechanically connected to said remaining end of said tube and movable relative to said valve body between open and closed operating positions, said valve body and control member having fluid conduits therein arranged to permit fluid communication in said open position and to prevent fluid communication in said closed position; and means carried by said support for obtaining indications of fluid pressure in the formation of interest.

14. An earth formation fluid sampler comprising: a

' support adapted to be positioned adjacent a formation of interest; means in said support defining a gun bore; a projectile in said gun bore; means in said gun bore for impelling said projectile toward and into the selected formation thereby to secure said projectile in the formation; a flexible, effectively extendable member having one end mechanically connected to said projectile; and a pull-actuated mechanism in said support including a movable member mechanically connected to the remaining end of said flexible member and responsive to relative displacement between said support and said flexible member to alter the operative condition of said pull-actuated mechanism.

15. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a formation of interest; means in said support for defining at least one fluid conduit; means in said support defining a gun bore; a projectile in said gun bore; means in said gun bore for impelling said projectile toward and into the selected formation thereby to secure said projectile in the formation; a flexible, effectively extendable member having one end mechanically connected to said projectile; and a pull-actuated valve mechanism in said support including a movable control member movable between a position opening said conduit and a position closing said conduit, said control member being mechanically connected to the remaining end of said flexible member and responsive to relative displacement between said support and said flexible member to move from one of said positions to the other.

16. An earth formation fluid sampler comprising: a

support adapted to be positioned adjacent a formation of interest; means in said support for defining at least one fluid conduit; means in said support defining a gun bore; a projectile in said gun bore; means in said gun bore for impelling said projectile toward and into the selected formation thereby to secure said projectile in the formation; a flexible, effectively extendable member having one end mechanically connected to said projectile; a pullactuated valve mechanism in said support including a valve chamber having at least a portion thereof opening into said gun bore, a movable control member positioned within said valve chamber and movable between a position opening said conduit and a position closing said conduit, said control member being mechanically connected to the remaining end of said flexible member and responsive to relative displacement between said support and said flexible member to move from one of said positions to the other.

17. An earth formation fluid sampler comprising: a support adapted to be positioned adjacent a formation of interest; means in said support defining at least one fluid conduit; means in said support defining a gun bore; a projectile in said gun bore; a propellant in said gun bore for impelling said projectile toward and into the selected formation thereby to secure said projectile in the formation; a flexible, effectively extendable member having one end mechanically connected to said projectile; and a pull-actuated valve mechanism in said support including a valve chamber having at least a portion thereof opening into said gun bore, a control member positioned within said valve chamber and movable between a position opening said conduit and a position closing said conduit, said control member being mechanically connected to the remaining end of said flexible member and responsive to relative displacement between said support and said flexible member to move from one of said positions to the other, said control member further having opposed, effective surfaces exposed to said gun bore so as to minimize movement of said control member upon actuation of said propellant.

References Cited in the file of this patent UNITED STATES PATENTS 2,055,506 Schlumberger Sept. 29, 1936 2,303,727 Douglas Dec. 1, 1942 2,441,894 Mennecier May 18, 1948 2,582,719 Ramsey Jan. 15, 1952 2,626,777 True Jan. 27, 1953 

1. AN EARTH FORMATION FLUID SAMPLER COMPRISING: A SUPPORT ADAPTED TO BE POSITIONED ADJACENT A SELECTED FORMATION; MEANS IN SAID SUPPORT DEFINING A SAMPLE-CONVEYING CONDUIT AND A GUN BORE; A FORMATION-PENETRATING PROJECTILE RECEIVED IN SAID GUN BORE AND HAVING A HOLLOW PORTION, SAID PROJECTILE FURTHER HAVING A FORWARD WALL PORTION ARRANGED TO OPEN SAID HOLLOW PORTION WHEN THE PROJECTILE IS IN THE FROMATION TO PERMIT FLUID FLOW; MEANS IN SAID GUN BORE FOR IMPELLING SAID PROJECTILE TOWARD THE SELECTED FORMATION; A FLEXIBLE TUBE IN SAID GUN BORE HAVING ONE END CONNECTED TO SAID PROJECTILE AND BEING FLUIDLY CONNECTED TO THE HOLLOW PORTION OF THE PROJECTILE EXTENDABLE BETWEEN SAID PROJECTILE AND SAID EFFECTIVELY EXTENDABLE BETWEEN SAID PROJECTILE AND SAID GUN BORE; A VALVE MECHANISM IN SAID SUPPORT FLUIDLY CONNECTING THE REMAINING END OF SAID TUBE AND SAID SAMPLE-CONVEYING CONDUIT AND INCLUDING A MOVEABLE CONTROL MEMBER MECHANICALLY CONNECTED TO SAID REMAINING END 